In the field of processing shellfish, especially shrimp, the shrimp are often sun dried for preservation. This is especially true of small and tiny shrimp that are otherwise difficult to market. To complete the processing of the shrimp after sun drying, it is necessary to remove the shells. The current methods employed for shell removal make this task difficult and time consuming. Often the end result of the shell removal process leaves the shrimp battered, broken and in pieces which significantly reduces the marketable volume of the shrimp, often as much as one-third. Thus, the price for unbroken dried shrimp is increased due to the shell removal difficulties which in turn reduces the demand. There is a need for an efficient and cost effective shell removal process for dried shrimp to allow more of the shrimp catch to remain intact after shell removal and at a reasonable cost.
Shells may be removed from small lots of dried shrimp by placing the dried shrimp in a cloth bag or sack and beating the shrimp filled sack against a hard object such as a sack or a tree. This method is time consuming and requires significant physical effort. Quantities of shrimp dust are produced as a result of the beating operation making it an unpleasant task. This method is suitable only for deshelling limited quantities of dried shrimp such as that which might be required by a sport shrimper or a very small commercial operation.
Efforts have been made to provide mechanical devices to facilitate removal of the shells. One such device employed is to provide a rotating tumbler of wooden slats and wire. The dried shrimp is placed into the tumbler which is then rotated. The shrimp pitched around in the tumbler falling against the wire and the wooden slats which dislodges the shells from the shrimp. The disadvantages of this procedure is that the shrimp is often broken, reducing the marketable volume of the shrimp as well as the appearance of the end product. In addition, the tumbling process is time consuming and their is little to no control over the shrimp dust and shells which fly everywhere and must be swept up.
Another method and apparatus for removing shells from crustacea is that described in U.S. Pat. No. 3,875,614 to Lapeyre. The Lapeyre patent describes an apparatus and method for removing shells by means of compelling the crustacea over a predetermined path having incisors for cutting the shells. The shells are then separated from the meat by flotation methods.
Another device is that described in U.S. Pat. No. 3,871,086 to Rutledge. Rutledge discloses a device for peeling hard shelled crustaceans by passing the deheaded headed crustacean through parallel cutting blades spaced apart a distance less than the body width of the crustacean.
Still another device for peeling warm pre-cooked shrimp has been described and illustrated in U.S. Pat. No. 4,862,794 to Lapeyre et al. The Lapeyre et al patent discloses a device having a peeling mechanism comprised of a series of rollers, some rubber coated and some metal, which squeeze the resilient warm shrimp to loosen and break away the shells. A disadvantage of the Lapeyre et al device is that it is best utilized when the shrimp are freshly cooked and hot and resilient.
Another device used to deshell shrimp is that disclosed in U.S. Pat. No. 3,528,125 to Jones, Jr. The Jones, Jr. patent discloses an apparatus for use on board a trawler that deshells raw shrimp by placing the shrimp through a compression conveyor and engaging the shrimp with a tined wheel which pulls the shrimp from the abraded compression action of the conveyor and thereby removing the shells.
Still another method and apparatus for deshelling cooked shrimp is illustrated in U.S. Pat. No. 3,466,699 to Willis et al. The Willis et al patent discloses a deshelling device which removes the shells from cooked shrimp by passing cooked shrimp, preferable boiled and so after boiling is completed, through a hopper and then between two vertically disposed rotating flexible discs which rotate between two horizontally disposed bars. The space between the bars is adjustable depending upon the size of the shrimp. The action of the rotating discs and the bars on the shrimp forces loose the shells. Shell removal is facilitated by continuously washing the shrimp and apparatus components with water. Washing the shrimp with water, which is required to implement the method of Willis et al, would not be suitable for peeling dried shrimp.
None of these devices disclose a process for the rapid and efficient removal of the shells from dried shrimp with a minimum of breakage. Consequently, a need exist for improvements in techniques to remove the shells from dried shrimp to minimize breakage and to eliminate the clean-up problems associated with conventional methods.